1. Field of the Invention
The invention pertains to a digital telecommunications exchange system with a control device including a memory and with a large number of termination circuits for connecting terminal devices via subscriber's lines and line circuits for the connection of communications lines leading to other telecommunications systems. The subscriber's and/or connection lines in each case have at least two user channels for transmission between the termination or line circuit and a coupling device of the telecommunications system, while the information of the data and/or signalling channel is provided for transmission between the connection or line circuit and the control device via a bus system.
2. Prior Art
A telecommunications exchange system is already known, as described in German Patent 34 05 011, including a switching arrangement for operating two-line digital subscriber's and/or connection lines of a telecommunications exchange system. The information on the data and/or signalling channel is transmitted between the connection or line circuit and the control device of the telecommunications exchange system via a bus system. To transmit the useful information, two user channels are available per connecting line with a transmission speed of 64 kbits/second in each case, while the data and/or signalling channel for transmitting communications-technical information has a transmission speed of 16 kbits/second.
The control device of such a telecommunications exchange system serves, among other things, to control the set-up and release of connections and for switching the connection pathways inside a coupling device. Besides other storage devices, the control device has a so-called customer data memory which, for example, contains information on the assignment of call numbers to respective connection addresses, authorizations and other connection-related information. The input of such information into the customer data memory can be done, for example, via a terminal device connected to a termination circuit or also via a data terminal connected to a bus system connecting several decentralized control devices with a control device higher in a subordination hierarchy, as is described for example, in German Patent 34 44 649.
Another possibility for inputting information into the customer data memory involves sharing a common service computer in a network formed by a large number of telecommunication exchanges The common computer has access via the signalling channel to the customer data memories of the individual telecommunication exchanges. Such a service computer is described, for example, in German Patent 21 39 275 or in the book Betriebsmessungen der Fernmeldtechnik, Teil 2: Vermittlungstechnik ("Operational Measurements of Telecommunications Engineering, Part 2: Telephone Switching Engineering"), Fachverlag Schiele und Schon, GmbH, Berlin 1976, on pages 360 and 361.
It would be desirable to provide a digital telecommunications exchange system of this type, wherein changes to customer data memory are facilitated, and in addition, other performance features are included. However, such capabilities should be consistent with, and should not interfere with, the control structure and operation of the exchange system. According to the present invention a computer with an input keyboard and a monitor is connected on a subscriber's line to the system. The control device of the system has an accessory control device which makes it possible to transmit data between the computer and the control device, so that a change in the data in the memory of the control device can be made by the computer, and/or the transmission of data from the memory to the computer is possible.
In this case, a certain part of the customer data in the memory of the control device may also be in the computer, in which case, for example, a change in the customer data in the computer is made first, and subsequently the change is made in the customer data in the memory of the control device of the telecommunications exchange system. Furthermore, the customer data memory can contain information which is required in the computer only temporarily. This information is called up when needed from the memory of the control device of the telecommunications exchange system by the computer. For example, the computer can function as a telephone book, in which case, besides the customer data, which is also available in the memory of the control device of the telecommunications system, additional information is contained in the computer which has no meaning in terms of telephone switching engineering. Via the accessory control device, it is also possible to initiate, e.g., connections between subscribers or between subscribers and communications lines via the computer.
The connection of computers with a monitor and keyboard to a private automatic branch exchange has already been described in European Patent Publication 266,151. However, here the computers connected to the subscriber's line cannot change customer data in the control device of the private automatic branch exchange nor is it possible to intervene in the switching processes via the hooked-up computer.
Finally, from German Patent Publication 2,120,562 is known a time-multiplex telephone exchange device in which a computer is connected to a control device of the exchange system, the computer supplementing the control device in terms of additional features. In this configuration, no change in customer data memory is possible.